Abstract: , Z80 CTC, two 8-bit general-purpose parallel ports and two chip select signals) operating at 10 MHz, a , of the Z80181 Z80181's counter/timer trigger inputs (Z80 CTC's channel 1) which is used to count the number of elapsed bit times. In counter mode, each active edge to the CTC's CLK/TRG1 input causes the downcounter of the CTC to be decremented. The /TRxC pin is programmed as BRG output and is connected to the , Drivers 230.4 kHz From Line Z80180 Z80180 CLK/TRIG1 CTC GLU Addr Decode Logic PIA2 PIA1 ...